In the early stage of computer development, the keyboard had been a fundamental input device. Although the computer has progressed tremendously, the keyboard is still not far away from the prototype until now. However, some manufacturers had developed self-luminous keyboards to convenience using the keyboard in a dim environment or provide a gorgeous and colorful effect. Now, the self-luminous keyboards are familiar to people and available in the market. Generally, LED is used as the light source in the very limited space of a keyboard. A R.O.C. patent No. 509955 disclosed a “Self-Luminous Keyboard”, which is a basic type self-luminous keyboard and has a keyboard unit and a backlight device. The backlight device is arranged below the keyboard unit and projects light upward to the keyboard unit. The light may be generated by LED or an electroluminescent sheet. A R.O.C. patent of License No. M330513 disclosed a “Light-Emitting Structure for Keyboard”, wherein side light sources are installed inside the keyboard in addition to the light-emitting elements arranged below the keys, and wherein a light-guide plate is used to make light emitted uniformly from below the keys. The prior-art patent has a key unit, at least one light-emitting element, and several light-guide plates. The light-guide plates are arranged on the same plane and below the key unit. The light-emitting element is arranged on the light-incident faces of the light-guide plates. A reflector, or the like, is arranged underneath the light-guide plates to reflect the light emitted by the light-emitting element to the key unit. Many other prior-art patents of self-luminous keyboards also have the backlight function and provide uniform illumination. All the self-luminous keyboards convenience using the keyboard in a dim environment and/or provide a gorgeous and colorful effect.
A R.O.C. patent of License No. M256532 disclosed a “Multi-Color Self-Luminous Keyboard”, which can provide multiple colors of light for different areas of the keyboard, wherein a multi-color electroluminescent sheet having several light-emitting areas is arranged below the keys. The light-emitting areas respectively provide different colors of light for different key groups, such as the functional key group, the numeric key group and the directional key group. However, the key areas illuminated by the colored lights and the colored lights illuminating the key areas are predetermined in fabrication. Thus, the users cannot define the key areas illuminated by the colored lights and the colored lights illuminating the key areas by themselves.
There have been various types of self-luminous keyboards. However, the light variations of the keyboards are predetermined by the manufacturers and very dull. Therefore, the self-luminous keyboard still has room to improve.